Piston-valve.



PATENTED APR. '3, 190 6.

W. SCHMIDT.

. PISTON VALVE.

. APPLI ATION FILED NOV. 7, 1904.

2 SHEETSSHEET 1.

B ff/2 awaif No. 816,607. PATENT ED APR. 3, 1906. W. SCHMIDT.PISTON'VALVE.

APPLIOATION PILEDNOV. 7 1904.

2 SHEEISSHEET 2.

fifn ass 65' 1' 1, W972 5 9,

UNITED dTATES PATENT @FFIQE.

.PiSTON VALVE.

Specification of Letters Patent.

Patented April 3, 1906.

Application filed November 7, 1904. Serial No. 231,768.

' To all whom it may concern.-

Be it known that I, vViLHnLM Seminar, 5. subject of the King of Prussia,German Einperor, and a resident of Nilhelmshohe, near Cassel, in theProvince of Hesse-Nassau, German Empire, have invented certain new anduseful Improvements in Packing or Check Ring Devices for Piston-Valves,of which the following is an exact specification.

My invention relates to improvements in packing or check ring devicesfor pistonvalves, and more especially to such checkring devices in whichsplit check or piston rings with radial bores are used, so as to allowthe steam to enter the inner side of the rings, thereby preventing thesplit rings from being compressed and pressed off from the inclosingwalls. As the pressure differences often change, it is desirable to keepthe split rings at .times in their proper position-that is to say, if inthe stretched state against the inclosing walls-and to release the ringsagain, if required.

The subject of my invention now consists in means for laterally pressingfast the peels. ing-rings in certain position, but at times releasingthe rings again. F or this purpose acomparatively great lateral pressureis necessary, which is obtained by sparing out the piston-valve in themiddle down to the pis ton-rod and arranging upon this side of thepiston-valve a flexible or axially-movable pressure-plate of greatsurface, so that the inside steam-pressure can firmly press the rings incertain positions a ainst the outside surfaces of the piston-valve.

In order to make my invention. more clear, I refer to the accompanyingdrawings, in which Figure l is a longitudinal section through avalve-chest and a piston-valve arranged therein according to myinvention. Fig. 1 shows a further constructional form of my piston-valvein a longitudinal section. Figs. 2 to 5 illustrate different positionsof the piston-valve and one of its split rings with regard'to a port.

In the drawings, Fig. 1 shows a pistonvalve consisting of two parts a(1, carried by the valve-rod a. In this arrangement 1 is a flat splitring arranged in a circumferential groove 9 and bearing against thesurfaces 5 of the valve a. The split ring is provided in known mannerwith small radial bores r, so as to allow the gas or steam to enterbehind the split ring, whereby at times this ring is valve a.

released and only gradually pr essed against the walls of thevalve-chest. g is an elastic plate partially movably mounted upon therod a and bearing with its outer edge against the gas-pressure side ofthe split ring Z.

My improved piston-valve operates in the following manner: During thesteam-admitting period steam can flow through the bores r to the innerside of the packing-ring and in the annular space between the plate 9and the valve-body a, and the same pressure is acting before and behindthe said plate. (See Fig. 2.) Therefore the ring Z is released from theplate 9 and pressing against theedge b of the part a does not takeplace. During the ex ansion period the pressure on the inner si e of thering is reduced. As the plate 9 is flexible and the steam-pressure restsu on the whole outer surface of the plate 9, the atter will more or lesspress against the s lit ring, thereby pressing the latter more or essagainst the surface I) of the piston-valve, thus insuring the momentaryposition of the packing-ring. (See Fi s. 3 to 5.) When the steam iscompressed int e steam-cylinder, the pressure arises on the inner sideof the ring in consequence of the bores 1', and the plate 9 releasesagain the latter.

In Fig. 1 a step-like split rin l is shown bearing against the surfaceI) of the piston- This ring Z is also rovided in known manner with smallradia bores '1 so as to allow the steam to enter behind the split ring.At the pressure side of the s lit ring a, pressure-plate g is provided,whio is somewhat axially rnova le upon the sleeve a? of the valve (1.Also in this arrangement the gas or steam can press upon the wholeinside surface of the pressure-plate, whereby the split ring isaccording to the gas-pressure resent more or'less pressed against thesuraces b of the piston, thereby holding the split ring in its momentaryposition.

Having thus fully described the nature of my invention, what I desire tosecure by L t ters Patent of the United States is- 1. A piston-valve forsteam or other fluid motive-power engines with two distinctvalve-bodies, each of them consisting of a cylindrical part a and amovable plate, and a packing-ring having radial bores, the cylindricalpart (1 having a circumferential groove for putting in the .plitpacking-ring, for the purpose as describe 2. A piston-valve for steam.or other fluid motive power engines with two distinct ITO valve-bodies,each of them consisting of a cylindrical part a, an elastical platepartially movable and a packing-ring having small radial bores, thecylindrical part 0 having a circumferential groove for putting in a slit packing-ring, for the purpose as describe 3. A piston-valve forsteam or other fluid motive-power engines with two distinct valve-bodies, each of them consisting of a cylindrical part a, a movableplate, forming an annular space together with the part a, and'aasking-ring having small radial bores, the cy indrical part 0 having acircumferential groove for putting in the split packingring, the smallradial bores therein serving for compensating the steam-pressure on theinner and outer side of the packing-ring, for the purpose as described.

4-. A piston-valve for steam or other fluid motivepower engines with twodistinct valvebodies, each of them consisting of a cylindrical part a,an. elastic plate partially movable, forming an annular space togetherwith the part a and-a packing ring having small radial bores, thecylindrical part a having a circumferential groove for putting in thesplit packing-ring, the small radial bores therein serving forcompensating the steam pressure on the inner and outer side of thepacking-ring, for the purpose as described.

In Witness whereof I have hereunto set my hand in the presence of twowitnesses.

WILHELM' SCHMIDT.

Witnesses: v

HENRY HASIER, WOLDEMAR HAUPT.

